Why do male dogs have 10 nipples if they can't have puppies.
The reason why males have nipples (humans and dogs and idk other animals) is because as an embryo everyone is a female until the Y cromosome kicks in! Thats why they have nipples! Look it up :)
Just like men have nipples, the same applies to dogs. The nipples are just vestigial. They make the male dog appear more beautiful and attractive. They have no specific purpose.
why dont male horses
Every living mammal;male or female has nipples.